Microneedle arrays provided with a plurality of microneedles are manufactured, for example, by a method to which a manufacturing process of semiconductors, such as etching, is applied. For example, Patent Document 1 discloses a method of this kind to which the manufacturing process of semiconductors is applied. The microneedle manufactured by this method is formed to be perpendicular to a flat surface (skin).
Therefore, as illustrated in FIG. 20, when a skin 203 is attempted to be pierced with a microneedle 201, since the surface of the skin 203 is deformed, the sufficient piercing cannot be performed, and as a result, a problem occurs that a liquid medicine 205 leaks out to the surface of the skin 203. In such a case, the microneedle 201 may be depressed more strongly against the skin 203 so as to be pierced, but this causes discomfort and pain to a patient.
Note that, in consideration of relieving the pain of patient during injection and effective injection of the liquid medicine 205, the preferable piercing depth of the microneedle will be around 100 to 500 μm under the skin.
In order not to cause discomfort and pain to the patient, and at the same time, in order to prevent the leakage of the liquid medicine 205 out to the surface of the skin 203, the microneedle 201 may be inclined relative to the skin 203 to perform piercing. Accordingly, the microneedle 201 can intrude into the skin 203 so as to prevent the leakage of the liquid medicine 205 out to the skin 203, and at the same time, since the tip of the microneedle 201 reaches only the shallow portion from the surface of the skin 203, the pain of the patient can be relieved.
Note that, Patent Document 2 discloses an example in which a syringe is inclined relative to the skin surface to perform piercing. Patent Document 2 shows a micro syringe of which needle can perform piercing at the angle of 45° or more relative to the skin surface.